In an energy storage module for vehicles such as a hybrid car and an electric car, a plurality of energy storage elements including positive and negative electrode terminals are lined up, and the electrode terminals of adjacent energy storage elements are connected to each other by bus bars included in a connection module so as to connect the plurality of energy storage elements in series or parallel. Usually, the interval between the electrodes (electrode pitch) of adjacent energy storage element varies, and therefore a technique is known to provide the connection module with a pitch adjustment means that adjusts the electrode pitch by extending and contracting the connection module in the line-up direction of the energy storage elements (see, e.g., Patent Document 1).